Bug 1204554 part 3.0 - Collect lcov output on the JSCompartment, and on the JSRuntime. r=terrence,bhackett

js/src/jscompartment.cpp

@@ -80,7 +80,8 @@ JSCompartment::JSCompartment(Zone* zone, const JS::CompartmentOptions& options =
     maybeAlive(true),
     jitCompartment_(nullptr),
     mappedArgumentsTemplate_(nullptr),
-    unmappedArgumentsTemplate_(nullptr)
+    unmappedArgumentsTemplate_(nullptr),
+    lcovOutput()
 {
     PodArrayZero(sawDeprecatedLanguageExtension);
     runtime_->numCompartments++;
@@ -91,6 +92,11 @@ JSCompartment::~JSCompartment()
 {
     reportTelemetry();
 
+    // Write the code coverage information in a file.
+    JSRuntime* rt = runtimeFromMainThread();
+    if (rt->lcovOutput.isEnabled())
+        rt->lcovOutput.writeLCovResult(lcovOutput);
+
     js_delete(jitCompartment_);
     js_delete(watchpointMap);
     js_delete(scriptCountsMap);

js/src/jscompartment.h

@@ -662,7 +662,8 @@ struct JSCompartment
     // Debugger API, or for the entire runtime.
     bool collectCoverage() const {
         return debuggerObservesCoverage() ||
-               runtimeFromAnyThread()->profilingScripts;
+               runtimeFromAnyThread()->profilingScripts ||
+               runtimeFromAnyThread()->lcovOutput.isEnabled();
     }
     void clearScriptCounts();
 
@@ -746,6 +747,11 @@ struct JSCompartment
 
   public:
     void addTelemetry(const char* filename, DeprecatedLanguageExtension e);
+
+  public:
+    // Aggregated output used to collect JSScript hit counts when code coverage
+    // is enabled.
+    js::coverage::LCovCompartment lcovOutput;
 };
 
 inline bool

js/src/jsscript.cpp

@@ -2936,6 +2936,11 @@ JSScript::finalize(FreeOp* fop)
     // JSScript::Create(), but not yet finished initializing it with
     // fullyInitFromEmitter() or fullyInitTrivial().
 
+    // Collect code coverage information for this script and all its inner
+    // scripts, and store the aggregated information on the compartment.
+    if (isTopLevel() && fop->runtime()->lcovOutput.isEnabled())
+        compartment()->lcovOutput.collectCodeCoverageInfo(compartment(), this);
+
     fop->runtime()->spsProfiler.onScriptFinalized(this);
 
     if (types_)

js/src/vm/CodeCoverage.cpp

@@ -6,13 +6,23 @@
 
 #include "vm/CodeCoverage.h"
 
+#include "mozilla/Atomics.h"
 #include "mozilla/IntegerPrintfMacros.h"
 
+#include <stdio.h>
+#if defined(XP_WIN)
+# include <windows.h>
+#else
+# include <unistd.h>
+#endif
+
 #include "jscompartment.h"
 #include "jsopcode.h"
+#include "jsprf.h"
 #include "jsscript.h"
 
 #include "vm/Runtime.h"
+#include "vm/Time.h"
 
 // This file contains a few functions which are used to produce files understood
 // by lcov tools. A detailed description of the format is available in the man
@@ -360,6 +370,68 @@ LCovCompartment::writeCompartmentName(JSCompartment* comp)
     return !outTN_.hadOutOfMemory();
 }
 
+LCovRuntime::LCovRuntime()
+  : out_(),
+#if defined(XP_WIN)
+    pid_(GetCurrentProcessId())
+#else
+    pid_(getpid())
+#endif
+{
+}
+
+LCovRuntime::~LCovRuntime()
+{
+    if (out_.isInitialized())
+        out_.finish();
+}
+
+void
+LCovRuntime::init()
+{
+    const char* outDir = getenv("JS_CODE_COVERAGE_OUTPUT_DIR");
+    if (!outDir || *outDir == 0)
+        return;
+
+    int64_t timestamp = static_cast<double>(PRMJ_Now()) / PRMJ_USEC_PER_SEC;
+    static mozilla::Atomic<size_t> globalRuntimeId(0);
+    size_t rid = globalRuntimeId++;
+
+    char name[1024];
+    size_t len = JS_snprintf(name, sizeof(name), "%s/%" PRId64 "-%d-%d.info",
+                             outDir, timestamp, size_t(pid_), rid);
+    if (sizeof(name) < len) {
+        fprintf(stderr, "Warning: LCovRuntime::init: Cannot serialize file name.");
+        return;
+    }
+
+    // If we cannot open the file, report a warning.
+    if (!out_.init(name))
+        fprintf(stderr, "Warning: LCovRuntime::init: Cannot open file named '%s'.", name);
+}
+
+void
+LCovRuntime::writeLCovResult(LCovCompartment& comp)
+{
+    if (!out_.isInitialized())
+        return;
+
+#if defined(XP_WIN)
+    size_t p = GetCurrentProcessId();
+#else
+    size_t p = getpid();
+#endif
+    if (pid_ != p) {
+        pid_ = p;
+        out_.finish();
+        init();
+        if (!out_.isInitialized())
+            return;
+    }
+
+    comp.exportInto(out_);
+    out_.flush();
+}
 
 } // namespace coverage
 } // namespace js

js/src/vm/CodeCoverage.h

@@ -101,6 +101,43 @@ class LCovCompartment
     LCovSourceVector* sources_;
 };
 
+class LCovRuntime
+{
+  public:
+    LCovRuntime();
+    ~LCovRuntime();
+
+    // If the environment variable JS_CODE_COVERAGE_OUTPUT_DIR is set to a
+    // directory, create a file inside this directory which uses the process
+    // ID, the thread ID and a timestamp to ensure the uniqueness of the
+    // file.
+    //
+    // At the end of the execution, this file should contains the LCOV output of
+    // all the scripts executed in the current JSRuntime.
+    void init();
+
+    // Check if we should collect code coverage information.
+    bool isEnabled() const { return out_.isInitialized(); }
+
+    // Write the aggregated result of the code coverage of a compartment
+    // into a file.
+    void writeLCovResult(LCovCompartment& comp);
+
+  private:
+    // When a process forks, the file will remain open, but 2 processes will
+    // have the same file. To avoid conflicting writes, we open a new file for
+    // the child process.
+    void maybeReopenAfterFork();
+
+  private:
+    // Output file which is created if code coverage is enabled.
+    Fprinter out_;
+
+    // The process' PID is used to watch for fork. When the process fork,
+    // we want to close the current file and open a new one.
+    size_t pid_;
+};
+
 } // namespace coverage
 } // namespace js
 

js/src/vm/Printer.h

@@ -133,7 +133,7 @@ class Fprinter final : public GenericPrinter
     // Initialize this printer, returns false on error.
     bool init(const char* path);
     void init(FILE* fp);
-    bool isInitialized() {
+    bool isInitialized() const {
         return file_ != nullptr;
     }
     void flush();

js/src/vm/Runtime.cpp

@@ -176,6 +176,7 @@ JSRuntime::JSRuntime(JSRuntime* parentRuntime)
     simulator_(nullptr),
 #endif
     scriptAndCountsVector(nullptr),
+    lcovOutput(),
     NaNValue(DoubleNaNValue()),
     negativeInfinityValue(DoubleValue(NegativeInfinity<double>())),
     positiveInfinityValue(DoubleValue(PositiveInfinity<double>())),
@@ -242,6 +243,7 @@ JSRuntime::JSRuntime(JSRuntime* parentRuntime)
 
     PodArrayZero(nativeStackQuota);
     PodZero(&asmJSCacheOps);
+    lcovOutput.init();
 }
 
 static bool

js/src/vm/Runtime.h

@@ -39,6 +39,7 @@
 #endif
 #include "js/TraceableVector.h"
 #include "js/Vector.h"
+#include "vm/CodeCoverage.h"
 #include "vm/CommonPropertyNames.h"
 #include "vm/DateTime.h"
 #include "vm/MallocProvider.h"
@@ -1056,6 +1057,9 @@ struct JSRuntime : public JS::shadow::Runtime,
     /* Strong references on scripts held for PCCount profiling API. */
     JS::PersistentRooted<js::ScriptAndCountsVector>* scriptAndCountsVector;
 
+    /* Code coverage output. */
+    js::coverage::LCovRuntime lcovOutput;
+
     /* Well-known numbers held for use by this runtime's contexts. */
     const js::Value     NaNValue;
     const js::Value     negativeInfinityValue;